All four are expected to appear at Liverpool magistrates’ court on Monday after being charged in the operation, led by detectives from Titan, the north-west’s regional organised crime unit.

A fifth man, a 22-year-old from Huyton, has been questioned and released on police bail pending further enquiries.

The men were arrested on Friday after a police operation led to the discovery of just over 160kg of suspected drugs in a flat in Lowbridge Court, just off Speke Road in Garston, and a tyre fitting firm in Huyton. Police said the substances, which are being examined by police, had a potential street value of up to £25m.